U.S. Pat. No. 3,983,227, Tofe and Francis, discloses the use of dry powder mixtures of reducing salts with a great variety of organophosphonate bone-seeking carriers to prepare bone scanning agents from radioactive pertechnetate solutions. The methanehydroxydiphosphonates used herein are included among the myriad types of phosphonates taught by patentees to be useful in dry mixtures suitable for the preparation of bone scanning agents.
The references relating to bone mineral-seeking agents and their use with .sup.99m Tc do not suggest the special advantages of methanehydroxydiphosphonate in radiodiagnostic products used for targeting bone material. For example, the reference which mentions methanehydroxydiphosphonate in bone scanning agents (U.S. Pat. No. 3,983,227) does so only as part of a rather general listing of a variety of organophosphonates, and only in the context of the powder mixture-type of product.
It has now been discovered that methanehydroxydiphosphonate, when used in the manner disclosed herein, unexpectedly provides both sharp bone mineral images and excellent lesion detection. Moreover, the methanehydroxydiphosphonates are superior to the other well-known organic phosphonates when used with .sup.99m Tc to image myocardial infarcts which, in the acute phase, are associated with high levels of calcium.